1. Field of the Invention
The present invention relates to a small type imaging lens array, and more particularly to an imaging lens array consisted of four lenses that are arranged at predetermined intervals.
2. Description of the Prior Arts
Since the image pick up lens has an increasingly wide range of application, plus the consumer electronic industrial is growing fast, the small image pick-up lens is accordingly found in great demand in different fields, particularly in photographic cell phone, digital camera, or auto's detection system for parking or other purposes.
A photosensitive element for a digital fixed focus lens array is merely of charge coupled device (CCD) type or CMOS type Complementary Metal Oxide Semiconductor, and its light sensitivity will be reduced sharply with the increase of exit angle of the lens. Therefore, the digital fixed focus lens array usually comprises 3-4 pieces of lens. However, this type of lens arrangement still has some technical defects as follows:
First, a first lens of the existing lens arrays is a double convex lens, while a second lens thereof is a double concave lens, and the first and second lenses will have an excessive ability, causing instability to the whole system.
Second, since the first and second lenses are double convex lens and double concave lens, respectively, and they are made of glass and are adhered to each other, plus the outer diameters of the first and second lenses are very small (small lens), the adhering work for adhering them together will not be easy. And as a result, the production cost for making this lens array will be high and the yield rate will be relative low.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.